A small but damaging tornado outbreak impacted northern Texas, south-central Oklahoma, northern Louisiana, and northern Alabama in mid-May 2013. The outbreak was the result of an upper-level shortwave trough that tracked across the Southern Plains of the United States. An associated low-pressure area and atmospheric instability resulted in the formation of tornadoes across northern Texas and Oklahoma on May 15. Afterwards the storm system weakened as it tracked eastward, though six additional tornadoes were reported in Texas, Louisiana, and Alabama in the two days following May 15. Over a period of nearly two days, the storm system produced 26 tornadoes in four states. The strongest of these was an EF4 tornado which struck Hood County, Texas on May 15. However, on May 16 and May 17 no tornadoes were confirmed to have been stronger than EF1 intensity. In addition to tornadoes, large hail was reported, peaking at in diameter near Mineral Wells, Texas on May 15.

The EF4 tornado in Hood County, Texas, accounted for all six deaths caused by the severe storms, making it the first deadly tornado event in Texas since the 2007 Piedras Negras-Eagle Pass tornadoes. An additional 63 people were injured, many of which were due to the same EF4 tornado. A second tornado, rated EF3, was similarly damaging and impacted areas southwest of Cleburne, Texas, injuring seven. Damage across the four states due to the storm system reached roughly $272 million in damage.

Meteorological synopsis

The outbreak was caused by an upper-level shortwave trough that moved northeastward from Mexico into the Southern Plains states during the nighttime the morning of May 15. The Storm Prediction Center (SPC) in Norman, Oklahoma, a division of the National Weather Service, initially issued a slight risk of severe thunderstorms early that morning over northwestern Texas, for a threat of large hail and damaging winds.Severe Weather Outlook at 12:53 p.m. CDT on May 15, 2013 A low-pressure area associated with the trough moved over Oklahoma that day, producing light to moderate rainfall and non-severe thunderstorms across that state into parts of North Texas. Later forecasts expanded the slight risk further into northern and Central Texas, and later into far southern Oklahoma, and indicated an enhanced risk of a few isolated tornadoes in North Texas.Severe Weather Outlook at 11:38 a.m. CDT on May 15, 2013

The atmosphere began to destabilize due to a decrease in cloud cover over western and central Texas; the sunshine and heating, combined with sufficient wind shear and abundant low-level moisture, combined to produce a very unstable air mass. The SPC issued a severe thunderstorm watch from southern Oklahoma to central Texas that afternoon around 3:00 p.m. CDT.Texas Tornadoes: As They Happened , The Weather Channel, May 17, 2013. Supercells broke out in parts of northwestern Texas during the late afternoon hours, one of which developed the first tornado of the day at 5:38 p.m., near Belcherville in Montague County. A second tornado spawned by the same storm, rated as an EF1, touched down near Lake Amon G. Carter, damaging four homes and destroying one. As forecasters realized that conditions now favored tornadic activity, the SPC issued a tornado watch from far southern Oklahoma into central Texas at 6 p.m. CDT, replacing parts of the original severe thunderstorm watch.

At 7:13 p.m. CDT, storm spotters reported a large tornado on the ground near Millsap in Parker County, which caused roof damage to several homes in the town. This tornado remained on the ground as another tornado began to intensify near Mile Marker 409 on I-20 southeast of Weatherford, Texas at 7:19 p.m. NWS doppler radar briefly detected both tornadoes, indicating the storm was a cyclical supercell (a type of supercell that can produce successive tornadoes), before the Millsap tornado finally dissipated.

An EF4 tornado hit the town of Granbury, Texas in Hood County around 8 p.m. CDT, damaging or destroying around 100 homes and killing six people, with the most severe damage occurring in the Rancho Brazos neighborhood; the Granbury storm was the first violent tornado to hit North Texas since an F4 tornado killed three people in Lancaster in Dallas County on April 25, 1994.Hood County twister one of the deadliest tornadoes in the last 50 years, Fort Worth Star-Telegram, May 17, 2013. The supercell that produced the Granbury tornado later spawned a very large EF3 tornado that hit the Fort Worth suburb of Cleburne in Johnson County around 9:30 p.m. CDT, producing its most significant damage just east of Lake Pat Cleburne.Cleburne mayor: Three EF-3 tornadoes damage or destroy 600 homes , WFAA, May 16, 2013. The last twister of the outbreak touched down at 12:19 a.m., producing EF1 damage in the Ellis County town of Ennis, Texas, south-southeast of Dallas. In total, the system produced at least 16 tornadoes that afternoon and evening across north and central Texas, from Montague to Coryell counties.The 16 tornadoes that occurred Wednesday defied predictions, The Dallas Morning News, May 16, 2013.

The system continued to spin up tornadoes on May 16 and 17, though not of the same severity as the storms that occurred on the 15th, each causing only minor to moderate damage of EF0 and EF1 intensity. Four additional tornadoes occurred near the Shreveport metropolitan area on May 16, two of which touched down near Waskom, Texas, and two in Caddo Parish near the towns of Greenwood and Stonewall, Louisiana.Thursday's storms brought 4 tornadoes to ArkLaTex, KSLA-TV, May 17, 2013. Retrieved May 18, 2013. Two short-lived tornadoes touched down in Limestone County, Alabama on May 17, causing scattered damage to trees, roofs and a barn.Friday storms across Alabama cause small tornadoes, heavy rains; wet weather expected to continue Saturday, AL.com, May 18, 2013.

Confirmed tornadoes

May 15 event + List of confirmed tornadoes – Wednesday, May 15, 2013EF#LocationCounty / ParishStateStart Coord.Time (UTC)Path lengthMax widthSummary EF0WNW of BelchervilleMontagueTX2233 – 2236A brief tornado caused damage to a ranch. EF0SW of PriddyMillsTX2314 – 2318This tornado remained over open fields and downed several trees. EF0WNW of AdaPontotocOK2334 – 2335A mobile home was damaged and several trees were downed. EF0SSE of Mineral WellsPalo PintoTX2341 – 2342A brief tornado caused no damage. EF1NE of NoconaMontagueTX2350 – 2355A mobile home slid off of its foundation, a few site-built homes were damaged, and several trees were downed near Lake Nocona. EF1WSW of SunsetMontagueTX2351 – 2358Five homes were damaged, one of which was destroyed, a golf course clubhouse was destroyed, and many trees were downed south of Lake Amon G. Carter. One person was injured. EF1Southern MillsapParkerTX0003 – 0019Several homes and barns were damaged and power lines were downed. EF0WSW of Illinois BendMontagueTX0018 – 0020A brief tornado damaged a home and downed several trees northwest of St. Jo. EF0E of MillsapParkerTX0022 – 0025A brief tornado north of Brock remained over open fields and caused no damage. EF0NNW of BridgeportWiseTX0035 – 0037A brief tornado north of Alvord stayed mostly over open land and only downed a few trees. EF0E of DennisParkerTX0053 – 0056Numerous barns and mobile homes were damaged or destroyed and numerous trees were downed south of Weatherford and southwest of Annetta. EF4Southeastern GranburyHoodTX0058 – 01116 deaths – See article on this tornado – 54 people were injured. EF0SSW of AledoParkerTX0105 – 0107A brief tornado caused no known damage. EF1Pecan PlantationHood, JohnsonTX0109 – 0121This tornado produced mostly minor damage in the Pecan Plantation community before crossing the Brazos River and dissipating. EF0NW of CressonJohnsonTX0119 – 0122A brief tornado damaged a billboard and a few farm buildings. EF0NNE of Evant (1st tornado)HamiltonTX0134 – 0136This was the first of two brief tornadoes that occurred simultaneously, although no damage was reported. EF0NNE of Evant (2nd tornado)HamiltonTX0135 – 0137This was the second of two brief tornadoes that occurred simultaneously, although no damage was reported. EF3SSW of CleburneJohnsonTX0212 – 0223See section on this tornado – Seven people were injured. EF0ESE of CleburneJohnsonTX0245 – 0249Five manufactured homes suffered roof damage and several trees were downed.

May 16 event + List of confirmed tornadoes – Thursday, May 16, 2013EF#LocationCounty / ParishStateStart Coord.Time (UTC)Path lengthMax widthSummary EF1EnnisEllisTX0505 – 0512A total of 17 homes were damaged, with 4 being destroyed. Another 55 commercial properties were damaged, with 20 suffering severe damage. One person was injured. EF1W of WaskomHarrisonTX1920 – 1924Several metal buildings were damaged and trees were downed. One person was injured. EF1SSE of WaskomHarrisonTX1934 – 1936A tornado caused minor damage to metal buildings, construction equipment, and a few houses. Several trees were downed as well. EF1ESE of GreenwoodCaddoLA1939 – 1950Many trees were downed, several of which caused damage to mobile homes and site-built homes. One person was injured. EF1NNE of StonewallCaddo, DeSotoLA2005 – 2009A brief tornado near a broad area of straight-line winds downed several trees.

May 17 event + List of confirmed tornadoes – Friday, May 17, 2013EF#LocationCounty / ParishStateStart Coord.Time (UTC)Path lengthMax widthSummary EF0S of AthensLimestoneAL1900 – 1907An intermittent tornado downed trees and shifted wooden front porch pillars at a house. It then skipped northeast, where it ripped metal signs and siding off of a metal pole before dissipating. EF0SW of ArdmoreLimestoneAL1945 – 1946A very brief tornado caused roof damage to several houses and a barn. One brick house sustained structural damage to its bricks and foundation and several trees were downed. EF0N of CrawfordDawesNE2154 – 2200No damage was reported. EF0WSW of WindomCottonwoodMN2245 – 2247A brief tornado caused no damage. EF0S of MilomaJacksonMN2310 – 2312A brief tornado caused no damage. EF0NW of Eliasville (1st tornado)YoungTX0034 – 0037A tornado occurred over open fields and caused no damage. EF1NW of Eliasville (2nd tornado)YoungTX0050 – 0053A house suffered significant damage to its roof and back porch.

Granbury, Texas

This violent, deadly tornado touched down on Apache Trail Court at EF0 intensity, dealing minor damage to homes before crossing Lake Granbury and hitting electrical lines at EF0 intensity. The tornado then began to rapidly intensify as it reached De Cordova Ranch Road where it would rapidly intensify as it completely destroyed a manufactured home, moving into the Ranchos Brazos subdivision and across Canyon Road and Sagecrest court, collapsing the walls of homes at EF3 intensity before reaching EF4 intensity for the first time as it destroyed a well-built home. The tornado would then weaken slightly back to EF3 intensity as it crossed Ranchview Drive, Highview Court and Echo Trail, completely sweeping mobile homes and collapsing multiple frame homes before reaching Sundown Court where two two-story well-built homes, at least one of which was properly secured with anchor bolts, were completely swept away.

The tornado would continue across farmland, destroying trees and a barn at EF1 intensity before intensifying to EF2 strength as it debarked multiple trees and ripped the roof off of a barn house. The tornado would continue to damage trees at EF0-EF1 intensity before reaching EF2 intensity again as more trees were debarked before rapidly weakening and dealing its last damage at EF1 intensity on Bob White Drive where multiple farm buildings suffered minor damage and a manufactured home was damage as well.